1. Field
One or more embodiments described herein relate to a three-dimensional semiconductor memory device.
2. Description of the Related Art
Semiconductor devices have been highly integrated to provide excellent performance, but not without substantial cost. One factor affecting cost relates to integration density, e.g., the cost of manufacture tends to increase in direct proportion to the integration density of semiconductor devices.
The integration density of two-dimensional (2D) or planar semiconductor devices may be determined by the area occupied by its unit memory cells. The area occupied by unit memory cells depends on the technique used to form fine patterns. Currently, extremely high-priced apparatuses are used to form fine patterns.
Three-dimensional (3D) semiconductor memory devices have been developed in an attempt to overcome the above-noted drawbacks. However, the production of 3D semiconductor memory devices is expensive compared to 2D semiconductor devices. Also, current 3D semiconductor memory devices have reliability concerns.